[clang-tools-extra] [clang-tidy] Add `readability-redundant-tag` check (PR #210007)

[Oliver Stöneberg via cfe-commits]

firewave wrote:

We should also have a test for usage in templates:

```cpp
struct Struct{};

template<typename T> void tf();

void f()
{
    tf<struct Struct>();
}
```

https://github.com/llvm/llvm-project/pull/210007